I have 2002 toyota corolla{166,000} which lags on acceleration; it runs smooth but has low power output; sometimes slight hesition on turns when eng is cold. The local dealership says that knocking noise is from eng pulley bearing and sometimes sounds like a pinging

It has new iriduim plugs, air filter; pcv valve, new cat & 02 sensors & tranny seems to be ok. i have also had fuel injectors cleaned. Any ideal what problem could be? The fuel filter or pump has never been changed. Chek eng light did come on as ineffeciecnt cat bank one so replaced the cat. This is a puzzle to me. I cannot afford a new car. Rob